Dengue strain shift: Den-2 takes centre stage, causing complications

Over 75% of this year's dengue patients have been infected with the dengue virus serotype 2 (Den-2), a study by the virology department of the National Institute of Laboratory Medicine and Referral Centre (NILMRC) has found.

In a notable development, some patients have been identified as being simultaneously infected with both Den-2 and Den-3 serotypes, in addition to the cases involving only Den-3.

On the other hand, no instances of patients infected with Den-1 and Den-4 serotypes have been reported this year.

Experts said there are four types of dengue – Den-1, Den-2, Den-3, and Den-4. Once a person is infected with a type of dengue, they develop immunity against it. But when infected with another type, the situation turns severe.

Given the high prevalence of Den-2 and the fact that many patients are being infected for the second and third time, complications associated with dengue are more this year, experts feel.

Dr Arifa Akram, an assistant professor of virology at the institute, told The Business Standard that patients with the Den-2 serotype are vulnerable to dengue shock syndrome, while those with the Den-3 serotype are susceptible to dengue hemorrhagic fever.

During a recent event, Professor Dr ABM Khurshid Alam, director general of the Directorate General of Health Services (DGHS), highlighted that this year, dengue shock syndrome has been a leading cause of fatalities.

Prime Minister's Personal Physician and Emeritus Professor Dr ABM Abdullah told TBS that dengue shock syndrome means that the blood pressure of a person affected by dengue drops very quickly, the hands and feet become cold, there is no urination for a long time, and the patient becomes unconscious.

"If the patient remains in shock for long, multi-organ failure occurs. That is why, more patients are now dying from dengue shock syndrome. Therefore, if anyone suffers from fever, they have to be given more liquid at home to stop them from going into shock," he added.

The researchers from the National Institute of Laboratory Medicine and Referral Centre analysed 200 samples to determine the prevailing serotype of dengue virus afflicting patients.

Among the samples, 151 showed the presence of serotype 2, 37 indicated serotype 3, and a combination of serotypes 2 and 3 was found in 12 samples.

Meanwhile, dengue patients' hospitalisation and deaths have surpassed all previous records this year, with 13 more people dying and another 2,070 being hospitalised due to dengue fever across the country in the past 24 hours till Wednesday morning.

With the latest figure, a total of 506 dengue patients have died and 1,06,429 were admitted to hospitals this year.

Professor ABM Abdullah said the treatment for dengue remains consistent regardless of the specific serotype afflicting the patient. The key focus in dengue cases should be on effective fluid management.

Patients are advised to increase their fluid intake. However, it's crucial to seek medical attention if vomiting, a drop in blood pressure, or the appearance of a rash occurs.